now a report from london tonight. >> reporter: chaos as the crowds were watching the changing of the guard at buckingham palace. a man came forward brandishing knives and one to his neck. when he refused to put them down police came forward with a taser. bystanders were amazed how quickly it unfolded. jay he tased him and threw him to the ground. >> reporter: tourists captured it on their cameras and phone. police say the man is believed to be in his 50s. so far they haven't released any other information about him or his motive. >> and we are told the queen was not home at the time and witnesses say the band played on as the chaos unfolded. no one was seriously injured. >>> president obama wants the boy scouts to open up their membership to gay people. in an interview the president praised the scouts as a great institution and says no one should be bared from it. the boy scouts announced they considered replacing the longstanding ban on gays with a policy to let troop sponsors make their own decisions. >> a new study suggests it does get better for bullied gay teens. as they aged th